CERN AC Note (2000-03)-General description of the CNGS Project

5. CNGS and the environment

5.3 Effect on water resources

5.3.1 Industrial water consumption

Demineralized industrial water from the SPS will be used for cooling the proton beam magnet system. This water passes through a closed circuit. It is cooled in the SPS cooling systems by means of a heat exchanger.

The SPS cooling water comes from Lake Geneva via a special pipeline. The consumption at the CNGS will be only about 1% of that of the SPS.

5.3.2 Effects on aquifers

All the underground structures of the CNGS are being built in the molasse, which is a material that is in principle impervious to water. None of the structures are located within the perimeter of a water catchment area.

Given the fact that the access shaft to the CNGS structure will not pass through any aquifers, there is no risk of polluting community water supplies either during construction or while the CNGS facility is in operation.

5.3.3 Waste water disposal

Drainage water will be collected in four underground tanks. One of these will be located in the ventilation chamber, another at the end of the service tunnel, a third in the hadron stop chamber and the fourth in the second muon detection chamber. Checks of water quality will be made before any of the water is discharged from the tanks into the SPS or LHC drainage systems.

5.4 Noise and vibration from the work-sites

These are isolated nuisances occurring from time to time that should nevertheless be taken into consideration. The different sources of possible noise during the period of engineering work on the structures are as follows:

  • the movement of machinery and on-site equipment: transport of spoil is not permitted at night;
  • the possible use of explosives through technical imperatives. If this is necessary it will be confined to the strict minimum. In this case, every precaution will be taken by CERN and blasting will only take place in the daytime;
  • the increase in road traffic, in particular traffic connected with the transport of spoil.

Given the simultaneous existence of work-sites for CNGS and TI8, CERN is planning to install a noise abatement screen to protect nearby housing.

5.5 Transport, traffic and roads

The amount of spoil produced by work at the CNGS will total 67’000 m3 bulked material. The excavation work will last some two years; removal will require some 15 transports per day on average.

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